If Brady was 35 I would feel completely different about this. I firmly believe Brady will either be hurt, play poorly (by Brady standards). Sure, no signs have been pointing to this thus far. He has been very healthy. He's kind of a freak of nature (usually a red flag for me that something else is going on- let's not be naive people, practically everyone is on something). It's impossible to predict injury (most of the time), but I think one of three scenarios plays out:
1. NE is in need of a backup at some point in the next year or 2, and wishes they had JimmyG.
			2. NE is in need of a backup at some point and are thrilled they don't have JimmyG because he's a bust.
			3. NE doesn't need a backup over the next 2 years and they come out looking like geniuses. 
			I am somewhere between 1 and 2 because I am not really sure JimmyG is the best available QB this offseason, nor do I think he will be probowl/franchise quality. Many people feel like NE will be in scenario 3. That's fine, they're entitled to their opinion. I just think, chances are, when you have someone who is getting into the age most players don't even make it to, having some kind of a backup plan is a good idea. If they like Brissett more, then either: they don't feel highly of Jimmy G, or as mentioned earlier in here by 
@Bracie Smathers, they just happen to have 3 franchise QBs on their roster. Which is more likely? Because if they felt highly of JimmyG they would try to resign him regardless. You don't let the guy you think can lead your team for 10 more seasons walk because you think your 40 year old QB can play another year or two.